The disabling effects of brain damage in man were evaluated on a broad range of perceptual, learning. and memory functions. Changes in the intellectual behavior of neurologically handicapped individuals were evaluated before and after brain surgery and during electrical stimulation of the surface and depths of the brain. In contrast to these cases with confirmed brain injury, the effects of peripheral, sensory deficits were assessed in terms of possible neuropsychological dysfunctioning, and communicative disorders. BIBLIOGRAPHIC REFERENCES: Van Buren, J.M. and Fedio, P.: Functional representation on the medial aspect of the frontal lobes in man. J. Neurosurg. 44: 275-289, 1976. Frederick, G.C., Quinn, C.P., Gillin, J.C. and Wyatt, R.J.: Deprivation of rapid eye movement sleep and nesting behavior in rats. Physiol. & Behav. 18: 341-344, 1977.